Quantum Tunnelling Composite for Pressure Switching and Sensing in Smart Touch Phones
Quantum Tunnelling Composite (QTC) is a composite made from micron-sized metallic filler particles (Silicone Rubber) mixed into an elastomeric matrix. Quantum tunnelling composite is a flexible polymer that exhibits extraordinary electrical properties. In its normal state it is a perfect insulator, but when compressed it becomes a more or less perfect conductor and able to pass very high currents.
David Lussey invented QTC (Quantum Tunnelling Composite) in 1997. It had to be a “accidental” find when he tried to create an adhesive, with an electrical conductivity properties. QTC is made up of small nickel ions sealed in a rubbery polymer. As QTC is deformed in some manner, such as by pressing, bending, or twisting, the nickel particles get closer together, and the substance becomes a conductor. The more deformed it is, the closer the ions get and the better it conducts electricity.
Peratech’s Quantum Tunneling Composite (QTC) technology is a type of novel material, with its ability to improve the conductivity of the composite under all mechanical deformations, this modern composite technology offers a significant advantage in the development of sensing systems.
When compressed, the resistance changes drastically. When uncompressed, It acts as a natural electrical insulator. When a force is exerted it conducts electricity like a metal.
History of Quantum Tunnelling Composite based Smart Touch Phones:
First produced in 1996, QTC is a composite material made from conductive filler particles combined with an elastomeric binder, typically silicone rubber. The unique method of combining these raw materials results in a composite which exhibits significantly different electrical properties when compared with any other electrically conductive material.
QTC is usually available in pill or sheet form. QTC pills are nothing more than small slabs of the stuff. One layer of QTC, another layer of conductive fibre, and a third layer of plastic insulator make up the panels. QTC pills are pressure sensitive variable resistors, whereas QTC sheets, which transform easily between high and low resistance.
Types of Quantum Tunnelling Composite (QTC):
1. Elastomeric (Material: Silicone Rubber) (The particle move close together)
2. Ink / Coating Solvent or Aqueous Polymer
3. Granular Sensors
Working of Quantum tunnelling composite:
QTC usually comes in the form of pills or sheet. QTC pills are just tiny little pieces of the material. The sheets are composed of one layer of QTC, one layer of a conductive material, and a third layer of a plastic insulator. While QTC sheets switch quickly between high and low resistances, QTC pills are pressure sensitive variable resistors.
Application of Quantum Tunnelling Composite:
– Touch switches (sheet)
– Force/pressure sensors (pills)
– Motor speed control using force (pills)
Benefits of Quantum Tunneling Composite:
- QTC is a pressure/force sensing material. It can be easily integrated into existing products to enable force sensing opportunities and solutions.
- Product surfaces can be incorporated, coated or impregnated with QTC to impart the properties of force sensing into or onto the host surface.
- QTC material can be formed or moulded into virtually any size, thickness or shape, permitting redesign of product interfaces and providing improved ergonomics, aesthetics and user comfort.
- QTC is an enabling technology which is simple and reliable to use.
- QTC material is durable – it has no moving parts to wear out.
- QTC material is mechanically strong.
- QTC material can be made to withstand extreme temperatures limits.
- QTC material is versatile, both electrically and physically e.g. Its range and sensitivity can be altered. QTC material is also intrinsically safe – the material is a contactless switch, ideal for sparkless operation.
- QTC material can be directly interfaced to standard electronic and electrical devices.
- QTC material and/or technology can be customized for customer requirements, applications and products.